Microstructure formation of the nickel-based superalloy ABD900 after LPBF and its comparison with Inconel 718

Abstract

The paper presents the results of a study on microstructure formation and a comparative analysis of the nickel-based superalloys ABD900 and Inconel 718 manufactured by Laser Powder Bed Fusion (LPBF). In recent years, additive manufacturing technologies have been increasingly applied in high-tech industries due to their ability to produce components with complex geometries and high-performance characteristics. However, the use of conventional high-temperature alloys, originally developed for casting or thermomechanical processing, in additive manufacturing processes may be associated with several technological limitations, including cracking, porosity, and microstructural instability. In this context, considerable attention has been devoted to the development of new alloys specifically optimized for additive manufacturing. One such material is the nickel-based superalloy ABD900, developed using the Alloy By Design approach and intended for LPBF applications. A comparative analysis of porosity revealed that samples of Inconel 718 are characterized by pores predominantly in the range of 2–10 μm, with maximum sizes reaching 12–14 μm, whereas the ABD900 alloy exhibits an overall lower porosity. The pore sizes in ABD900 are mainly within the range of 2–12 μm, and no isolated larger pores were observed compared to the Inconel 718 samples. Microstructural analysis demonstrated the formation of a characteristic melt track morphology typical for the LPBF process. In the Inconel 718 samples, a more pronounced cellular-dendritic solidification structure was observed, whereas in the ABD900 alloy, certain regions of the microstructure are characterized by the formation of a fine cellular γ-Ni matrix. The obtained results confirm the potential of ABD900 for additive manufacturing applications and highlight the specific features of its microstructure formation in comparison with Inconel 718.